Acne, also known as whelk, acne vulgaris, pimple), is a common skin disease which can cause inflammation of human skin sebaceous glands or hair follicles. Spine-shape papules, from which white or creamy white broken rice like juice can be squeezed out, are formed in local lesions. Acne often occurs in young people, in both sexes. It is more commonly found in male than in female, but the age of onset in female is earlier than in male. Acne occurs mostly in face, forehead, cheek and nasolabial fold, next in chest, back and shoulder. Usually, the skin damage caused by acne does not have subjective symptom. Pain may be accompanied under severe inflammation reactions. Acne can be classified into acne, papule, pustule and nodular cyst. Acne affects 80-90% of teenagers. After adolescence, acnes often can be abated automatically or cured, except that acne persists in some patients into their thirties. Although acne has a tendency of self-healing, the acnes themselves and scars caused by the acnes without timely treatment may severely affect the life quality of patient and cause mental pressure and financial burden of patients. Attentions should be paid to these problems.
The development of acne is mainly related to the factors, such as excessive sebum secretion, the duct clog of folliculosebaceous, bacteria infections and inflammation reactions. After people enter into their adolescence, the level of androgen, especially testosterone, is increased rapidly, promoting development of sebaceous glands and a large secretion of sebum. At the meantime, the abnormal follicular keratosis of the sebaceous gland ducts causes the clog of ducts, dyssebacia and the formation of keratotic plug (i.e. micro-acne). Various microbes, especially Propionibacterium acnes, overgrow in hair follicle. The lipases generated by Propionibacterium acnes degrade the sebum into free fatty acids, promote the chemotaxis of inflammatory cells and mediators, and finally induce and aggravate inflammation.
Acne can be divided into inflammatory acne and non-inflammatory acne. The excessive sebum secretion and the clog of hair follicle usually cause non-inflammatory acne, i.e., pimple, while the overgrowth of bacteria in the pimples will induce inflammation and cause inflammatory acne. When the damage to the skin caused by inflammatory acne reaches dermis layer, scars (pockmarks) form.
However, at present, the drugs used for acne treatment mostly contain hormones and antibiotics. Although they can reach the effect of acne removing, they have relatively obvious side-effects and strong dependence, thus are not suitable for long-term use. Currently commonly used acne-removing products in the market choose salicylic acid, capryloyl salicylic acid, ethanol, fruit acid and the like as the main active ingredients for disinfection and anti-inflammation, avoiding formation of inflammatory acne. However, the ingredients, such as salicylic acid, capryloyl salicylic acid, ethanol and fruit acid, have relatively high irritation and often cause side-effects such as skin sensitivity, sharp pain and severe decrustation. Also, toleration will develop after long-term use. Additionally, acne-removing products using traditional Chinese medicine extract as active ingredients also exist on the market, but they are too mild, work slowly and have poor effects.